Extreme cold hasn’t killed region's stink bug horde

Friday

ROCKFORD — The dangerous cold that descended on the region in the past month canceled school, closed government buildings and sent people running inside, but it didn’t wipe out those pesky stink bugs.

“No way. We’ll still have stink bugs,” said Nick Seiter, research assistant professor of field crop entomology at the University of Illinois’ Department of Crop Sciences.

Seiter, who works with the U of I’s Extension program in Winnebago County, said there has been a misconception that the sub-zero temperatures and even lower wind chills would eliminate the area’s stink bug population.

The theory stems from a study that Virginia Tech entomologist Thomas Kuhar conducted during a harsh 2013-2014 winter season. Kuhar used buckets containing foam-insulated tubes and stink bugs to simulate the overwintering conditions endured by stink bugs in their dormant state. In that first set of buckets, Kuhar found that 95 percent of the bugs inside had died.

Kuhar theorized these bugs would have higher mortality rates because of the polar vortex conditions.

“That’s not an accurate number when you look at large scale,” Seiter said.

The National Pest Management Association used that 95 percent figure in a release it sent out, stating 95 percent of the stink bugs that hadn’t found a winter shelter may have been wiped out. Fast forward five years and that figure took on new life, only this time, some were claiming that “a study” showed 95 percent of stink bugs without shelter may have died from the sub-zero cold.

“Some of the major media outlets picked it up and cited it in a way I think was pretty misleading,” Seiter said. “They took the number that was eye-catching.”

There is a chance the area’s stink bug population could be affected by the past month’s polar vortex, but Seiter couldn’t predict by how much.

That’s because the invasive species, which isn’t harmful to people, go into a type of hibernation during the winter called diapause. They go reproductively dormant, he said, don’t eat and usually don’t move about. These bugs already had sought shelter in homes, businesses and protected areas outdoors, such as under tree bark, said Chris Mei, owner of Bug Lady Pest Control in Loves Park. That process begins in the fall, she said, so many bugs were not outside during the frigid weather. And those that were may have been protected, too.

“They just want to get in in the fall and spend the winter with you,” she said. “It may reduce some of them outside if they weren’t able to get out of the elements.”